And kempster



(No Model.)

J. E. KEBLYN. & K.:B. MILLER 2 Sheets- Sheet,v 1.

TELEPHGNE EXCHANGE SYSTEM.

Patented Mar. 23; 1897.

(No Model.) sheets-sheet 2.

J. E. KEBLYN sz K. B. MILLER. TELEPHONE EXCHANGE SYSTEM.

UNITED STATES Vw f PATENT OEEICE.

JAMES E. KEELYN, OF CHICAGO, ILLINOIS, ANI) KMPS'IER l. MILLER, OF I VASIIINGTON, DIS' RICT OF COLUMBIA.

TELEPHONE-EXCHANGE SYS-TEM.

SPECIFICATION forming 'part of Letters Patent No. 579,299, dated March 23, 1897.

Application tiled April 27, 1896. Seal No. 589,231x Vtlo model.)

To all 'whom t l2-Lay concern:

13e itltnou'n that we, JAMES E. KEELYX, of Chicago, Illinois, and KEnrsTEn 13. MlLLEn, of lashington, District of Columbia, citizens of the l'nited States, have invented new and usefulImprm'ementsin'leleplione-Exchange Systems, oi which the folloiving a specilication.

Our invention rela tes to divided-board teleihone-exchnnge systems wherein the connection of lno subscribers on different boards is effected by trunk-lines intercoimeetiug the boards instead of by the new common multiple-jack arrangement, and has for its object a construction of less complexity than those in use at present, and which Will, nevertheless, gire quicker and more reliable service. This object atta-ined by a new arrangement.- of trunking-circuits, and also by a peculiar and novel method of; grouping the operators an d their respective boards into overlapping districts, whereby confusion on the trunking and instruction circuits between the operators is largely avoided.

re terminate the subscribers lines lin groups of, say, one hundred each, each group occupying a separate board. These boards are numbered from l up and are divided into what we term districts Aof the first district are llos, l -i 7 l0 13, die.; those of the second district are 2 5 8 ll 14, ttc.; those of the third district are 3 G 012 l5, ttc. The boards are of such size and sc arranged that an operator sitting at any' one of them can-easibT reachthe springjaeks on herown board and also those on the adjoin ing boards at her right and left. It is thus seen that every operator, with the exception of the operators at each of the end boards', can reach one board in each of the three districts. For instance, the operator at board il has in Afront of her aboard belonging to district i3, at hei: lett a board belonging .to district 2, and at her right a board belonging to district l At each board are arranged pairs of plugs, each )air eonsistingof a calling and an answering plug connected together bj; a cord-circuit, yith the usual arrangement l'or switching in the calling-generator or the operators telephone set. Connected also to eac-h of these pairs ot plugs are branch ciroperator at that boa-rd inserts any disengaged ad jacent board, or she instructs the operator 4at that board in her own district which is nearest to the board on which the called subscribers line terminates to insert the transfer-plug ot' the corresponding trunk-line into the jack of the called subscriber. The two subscribers are thus connected for conversaf tion, and as the connectionon this particular trunk-line can be originated at only one board this line cannot be used again by operators at other boards for making other connections.V A separate instruction-eirenit is provided for each operatoigraml into this circuit any other operator belonging to the saine district canat will switch her own telephone. By this means each operatorcan communicate with any of the other operators belonging to her own district, but with no others. Y y

For detailed descrition of our invention reference must be ha( to the annexed drawings, 'which forni a part of this specification, and in whchj'- Figure l Vis a diagrammatic representation -ot the general scheme of trunloline arrange,

ment in a system Comprising twelve boards. Fig. Lshows the arrangement ol' the plugs 0f one trunk-line with respect to the boards on the first district, and also a separate instructioinuircuit between the operators. Fig. 3 relers to a slightiy-modilieil `lorm of our invention.

Reference heilig had to Fig. il, 'l l 3, die., f are the divided boards in which the subscribers' lines tmminate. As before stated, the boards are divided into preferably three districts. 'lhc .first district begins with boa-rd No. 1 and includes evcrythird board therefrom. likewise the second and third districts :o As will be seen in Fig. 2, plugs A B of each pair are connected by a cord-circuit l 2, containlng the clearing-out drop O. Connected l to the two sides of this cord-circuit are the branch wires 3 4, leading, respectively, to the two sides of the trunk-line 6. Connected in multiple to this trunk-line are the transferplugs C C C, distributed atall the other boards of the district to which this particular p' 'of plugs A B belongs. In likeA mann ach 2o board is provided with several pairs oii" lugs 'A B, each pair bein gconnected with transferplugs C C C, distributed at all the boards' of that district to which their particular originating pair A B belongs. This is shown in z5 one case only in Fig. 2, where the plugs A B on board 4 are connected bythe trunk-line 5 6 with the plugs C C C at boards 1 7 10,

dac, One complete set of trunk-lines in sho wir' in Fig.y 1,'where an initiating pair A B is 3o shown at every board, the pair at each board being connected by a trunk-line with the transfer-'plugs C C on every other board of the district to which that board belongs.

It Will-be noticed that the operators at-each of the end boards have boards .of only two Wdistricts Within their reach. lFor instance,

the operator at board l can reach only boards 1 and 2, and unless provision is made she will therefore have no transfer-plugsin ldis- 4o trict 3'within her reach; This is readily provided lfor by placing a blank board 0 lat the left of board l and another blank board 1l at the right of the board at the other end. Each of these blank boards is provided with trans- 4 5 fer-plugs froni the board belonging to the district to which they belong in exactly thesaine manner as the other boards. Thus the blank board OX. at the left of board l would belong to district 3 and would be provided with 'trans- 5'0 fer-plugs from other boards of that'd-istrict. In like manner blank board 1l at the right of board l0 would belong toI district 2 and would likewise be provided with transferplugs froin other boards of that district.-

5 5 These blank boards need have no springjacks, annunciators, answering-plugs, or operators sets, as they are provided simply to afford rooinz-for the transfer-plugs for 'the boards of thel district to which they belong..

It is obvious that the blank boards O and l1 .could be dispensedwith by placing the\ boards in a circle or in anysother closed iigure, so that the two end boards would be adjacent and the operator at each could therefore reach the transfer-plugs on boards at both her'right and left. By means of the cam Dl and the lever L the generator G or the'operators telephone set E may be connected in any well-known manner across the cord-circuit o f any initiating pair A B.

The particular form of circuit-changing switchshown is here illustrated for simplicity only. It will be understood that it is desirable in practice for this device to include means whereby Athe generator can vbe thrown into the circuit with either the answeringplug A or inthe circuit containing the calling and transfer plugs in multiple. Many of the circuit-changers now in Apractical luse would answer this -purpose,"and we have not deemed it advisable .to show anyone of them in detail. Each operator is also provided with a separate instruction-circuit I I', dsc., which leads from her telephone set E. to' a button K K', duc., at each of the other boards belonging to her ownd'istrict only. By pressing one of these buttons K K" any operator may connect her telephone set E with one of the in struction-circuits I I', leading to an-y operator lin her own district.

Asshown in Fig. 2, the operators at either of boards 1, 4, or 7 by pressing one of their respective buttons KK K vWould 'eonn,ect their telephone sets across the circuit I, thfus being able to communicate with the operator at board 10 by means of her tertiary coil T. Likewise the operators at boards 7, and l0 by pressing one oftheir respective buttons K K K may connect their telephones across the circuit I', thus being able to .ommunicate with the operator at board 4C'.

)nly two instruction-circuits are shown complete to avoid confusion,x'but it is to be understood that other and separate instruction-circuits lead from the 'several operators to' the,telephone sets of operators 1 and 7 in a like manner. Both of the other districts are provided with a similar system of instruction- IOC circuits, the systems of each district being entirely distinc I.

The operation of our system is a'sfollows: Suppose a subscriber at board et calls. The operator at that board inserts any disengaged answering-plug A into the corresponding jack and moves vthe lever L into a position to connect her telephone set E with the line of the calling-subscriberand ascertains the number desired. If the subscriber called for isat her own board or at either of the adjacent boards 3 or 5, she completes the connection herself by inserting the corresponding calling-plu g B of that pair into the jack of the called subscriber. The lever L is then operated to throw the generator-currentl on the line, thus signaling the called subscriber, when the connection is complete. If, however, the subscriber called for is at, say, board 8, the operator at board 4, after having inserted the plug A into the callin g-subscribers jack, presses the button Kef the instruction-circuit leading to operator 7 and tells her to place the plug C of that particular trunk-line into the jack of the called subscriber at board 8. The operator at board 7 then graspsthe plug C'With the IIO right hand and reaches over on board 8 to malte the desired connection'. If' the'called subscriber were on board 9, the operator at board 4 would com mn nicate with the operator of board l0, who would then make the desired connection with her left hand. Should the calling ,subscriber be at some boa-rd in district 2 or 3, for instance in boards 5 or 6, then the initial connection Wo uld be made by operators at board 5 or 6, respectively, who would in# structsome operator in their own respective district to make the final connection.

In the modification shown in Fig. 3 the separate calling-plugs at boards 1 7 l0 arev connected to the initiating pair A and B at board 4t by separate trunk-lines, instead of being connected in multiple to one trunk-line, as is shownin Figs, 1 andi). In this case a circuit-changer IVI is needed in order to connect anyparticular trunk-line with the initiating pair A B. Y

Suppose a call originated on board et which required a connection on one of the three boards Within the reach of operator No. 7. The operator at board 4, by means ot the cir-` cuit-changer H, would connect the trunk-line leading to board 7 With her pair A. B, and operator at board 7 would complete the con'- nection by means of thecorrespondin g plug Q. Having described vour invention, What We claim as new, and desire to secure by Letters Patent, -isl. In a telephone-exchange system divided boards, an answering and a calling plug cnnected by a cord-circuit at one of said boards, a trunk-line for interconnecting said boards, and transfer-plugs at one or more other boards, said cord-circuit and transfer-plugs being connected in multiple with said trunkline, substantially as described. 2. In a telephone-exchange system divided boards', an answering and a calling plug connected bya cord-circuitat one of said boards, a switching device whereby an operators telephone or a transfer-generato r may be connected to said cordecircuit, transfer-plugs at one or more other boards, and a ytrunk-line for interconnecting said boards, said cordcircuit and calling-plugs being connected in multiple with said truukline,`whereby a connection can be originated on said trunk-line at one board only, substantially as described. 3. In a telephone-exchange system, divided boards grouped into' overlapping districts, a connecting-plug at each board, a trunk-line for each district for interconnecting said boards, the plugs of one district being connected to the tru nir-line belonging to that district only, the arrangenient being such that a connection on a particular trunk-line may be originated on-ly on a board ot' the district to which that trunk-line belongs, While thc connection may be completed on a board o1 any district, substantially as described.

4. In'a-telephone-exchange system, divided 65 boards grouped into overlapping districts, an 4 answering and a calling plug connected by a cord-circuit at each board, transfer-plugs at each board, and vtrunk-lines foreach district connecting the cord-circuit at one board with one of said transfer-plugs at every other board of the same district only, substantially as described. Y

5. In a telephoneexchange system, divided boards grouped into separate overlapping districts, each district beginning on a certain board .and including every third board therefrom throughout the system, a -calling and an answering plug connected bya cord-cir cuit at each. board, transfer-plugs also at each board, and trunk-lines for interconnecting said boards, each of said trunk-lines leading from the. said cord-circuit to one or more of said transfer-plugs at boards of the same district only, substantially as described.

6. Ina telephone-exchange system, divided boards grouped into. overlapping districts,

trunk-lines for interconnecting said boards,

operators telephones one at each board, each connected to a separate instruction-circuit,

and means Wherebyany operatorstelephone Of a 'certain district may be looped into the instruction-circuit of any board belonging to that district only, so that an operator can communicate with the operators in herown district'only, substantiallyT as described.

7. In a telephone-exchange system, divided boards grouped into overlapping districts, an answering and a calling plug connected by a cord-circuit at each board, transfer-plugs at each board, trunk-lines for each district connecting the cord-circuit at one board with one `of said transfer-plugs at every other board of v the same district only; an operators telephone at each board each connected to a separate instruction-circuit, and means whereby any operators telephone of a certain district may be looped into the instruction-circuit of any 4board belonging to that district only; Where'- by a connection originating on any board must be completed by an operator of the saine district only, but may be so completed on a board of any district, substantially as` described.

8. In a telephone-exchange system, divided boards and subscribers line-terminals thereon, an answeringand a calling lug connected by a cord-circuit at one of sair boards, transfer-plu gs at one or more other boards, circuits leading from said cord-circuit to each of said" transfer-plugs, and ineans whereby any one of said circuits may be connected to said cordcircuit, substantially as described.

JAMES KELYN... KEMPSTER B. MILLER. Witnesses: 4

F. L. STEvENs,

WILLIAM A. BIsLANn.

ICO

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